In order to access phpPgAdmin directly via your domain name without having to access your cPanel first, you need to install phpPgAdmin on your hosting account.
The installation is very easy and consists of 3 simple steps:
2. Upload the package to your public_html folder.
By default the package will be extracted in a folder called phpPgAdmin-<version> where <version> corresponds to the phpPgAdmin version you downloaded. You can rename the folder to anything you want and then you will be able to access it directly via your domain name (e.g. www.yourdomain.com/phppgadmin).
To log in and manage a Postgre database, you first need to create the database and add a user to it. You can do this from your cPanel > PostgreSQL Databases. With the user(s) you create you will be able to log in to your newly-installed phpPgAdmin.